[gmx-users] g_energy => RMSD vs Fluctuation

[Chih-Ying Lin]

Hi
The definition of the Fluctuation is shown on the Manual, Appendix C, eqn (C.1)
The definition of the RMSD is as shown from the link.
http://en.wikipedia.org/wiki/Root_mean_square_deviation
The definition of the estimators is unclear though.

So, what is the definition of the estimators?

The following is showing one set of the results from g_energy.
=> The RMSD of Temp, Pressure, Kinetic En. correspond to their Fluct.
=> The RMSD of Potential and Total Energy do NOT correspond to their Fluct.


I think that the definition of the estimators of Temp, Pressure,
Kinetic En. are their average values, am I right?

How about the definition of the estimators of Potential and Total Energy ?
Thank you
Lin



Energy                      Average       RMSD     Fluct.      Drift  Tot-Drift
-------------------------------------------------------------------------------
Potential                   -196428    372.215    340.852    5.18038    518.043
Kinetic En.                 37754.5    219.122    219.116  0.0585484     5.8549
Total Energy                -158674    302.504    261.985    5.23893    523.899
Temperature                 301.814    1.75169    1.75164 0.000468047  0.0468051
Pressure (bar)              346.087    165.538    165.471   0.162984    16.2986
Heat Capacity Cv:      12.4724 J/mol K (factor = 3.36849e-05)